This research project is concerned with the organization of specific genes in the chromosome with the ultimate goal of understanding the mechanism responsible for the expression of these genes: Numerous approaches are being used: 1. the examination of the structure of specific cellular and viral genes in chromatin to discern those structural changes which occur within the chromatin complex; 2. the analyzation of the contribution of the primary sequence organization about the ovalbumin gene in reglating its expression in response to hormone; 3. the transfer of purified genes to study the functional and physical state of exogenous genes in a transformed host.